Plastic film, plastic bag and preparation method of plastic film

Abstract

The present disclosure provides a plastic film, including: a film A and a film B, where a material of the film A includes at least one selected from the group consisting of polylactic acid (PLA), poly(butylene adipate-co-terephthalate) (PBAT), and poly(butylene succinate) (PBS); the film B includes a base layer and a coating layer, and the coating layer covers the base layer; the film A and the film B are laminated; and a material of the coating layer is polyvinylidene chloride (PVDC) and a material of the base layer is cellulose, or a material of the coating layer is aluminum oxide and a material of the base layer is PLA. It has been found that the plastic film has excellent water resistance, gas tightness, and mechanical performance, is biodegradable, and can be widely used in food packaging bags.

1 . A plastic film, comprising: a film A and a film B, wherein a material of the film A comprises at least one selected from the group consisting of polylactic acid (PLA), poly(butylene adipate-co-terephthalate) (PBAT), and poly(butylene succinate) (PBS); the film B comprises a base layer and a coating layer, and the coating layer covers the base layer; the film A and the film B are laminated; and
 a material of the coating layer is polyvinylidene chloride (PVDC) and a material of the base layer is cellulose, or   a material of the coating layer is aluminum oxide and a material of the base layer is PLA, or   a material of the coating layer is PVDC and a material of the base layer is PLA, or   a material of the coating layer is aluminum oxide and a material of the base layer is cellulose.   
     
     
         2 . The plastic film according to  claim 1 , wherein the material of the film A comprises PLA and PBAT. 
     
     
         3 . The plastic film according to  claim 2 , wherein the PLA, the PBAT, the cellulose, and the PVDC in the plastic film are in a weight ratio of (10-20):(45-65):(20-35):(2-5). 
     
     
         4 . The plastic film according to  claim 3 , wherein the PLA, the PBAT, the cellulose, and the PVDC in the plastic film are in a weight ratio of (12-18):(50-60):(20-35):(2-5). 
     
     
         5 . The plastic film according to  claim 4 , wherein the PLA, the PBAT, the cellulose, and the PVDC in the plastic film are in a weight ratio of (12-18):(55-60):(24-32):(3-4). 
     
     
         6 . The plastic film according to  claim 5 , wherein the PLA, the PBAT, the cellulose, and the PVDC in the plastic film are in a weight ratio of (15-18):(55-60):(24-28):(3-4). 
     
     
         7 . The plastic film according to  claim 1 , wherein a surface of the plastic film is provided with an uneven pattern; the pattern has a roughness Ra of 0.1 mm to 0.2 mm; and in the pattern, a distance between a wave crest and a wave trough that are adjacent is 1.2 mm to 4 mm, and a height difference between a wave crest and a wave trough that are adjacent is 0.18 mm to 0.4 mm. 
     
     
         8 . The plastic film according to  claim 2 , wherein a surface of the plastic film is provided with an uneven pattern; the pattern has a roughness Ra of 0.1 mm to 0.2 mm; and in the pattern, a distance between a wave crest and a wave trough that are adjacent is 1.2 mm to 4 mm, and a height difference between a wave crest and a wave trough that are adjacent is 0.18 mm to 0.4 mm. 
     
     
         9 . The plastic film according to  claim 3 , wherein a surface of the plastic film is provided with an uneven pattern; the pattern has a roughness Ra of 0.1 mm to 0.2 mm; and in the pattern, a distance between a wave crest and a wave trough that are adjacent is 1.2 mm to 4 mm, and a height difference between a wave crest and a wave trough that are adjacent is 0.18 mm to 0.4 mm. 
     
     
         10 . A preparation method of the plastic film according to  claim 3 , comprising the following steps: 
 (1) according to a weight ratio, compounding at least one selected from the group consisting of PLA, PBAT, and PBS and then extruding to obtain the film A;   (2) according to a weight ratio, compounding the cellulose and then extruding to obtain a base layer of a cellulose film of the film B, and coating the PVDC on a surface of the base layer of the cellulose film to obtain the film B; and   (3) laminating the film A and the film B into the plastic film through an adhesive.   
     
     
         11 . A preparation method of the plastic film according to  claim 4 , comprising the following steps: 
 (1) according to a weight ratio, compounding at least one selected from the group consisting of PLA, PBAT, and PBS and then extruding to obtain the film A;   (2) according to a weight ratio, compounding the cellulose and then extruding to obtain a base layer of a cellulose film of the film B, and coating the PVDC on a surface of the base layer of the cellulose film to obtain the film B; and   (3) laminating the film A and the film B into the plastic film through an adhesive.   
     
     
         12 . A preparation method of the plastic film according to  claim 5 , comprising the following steps: 
 (1) according to a weight ratio, compounding at least one selected from the group consisting of PLA, PBAT, and PBS and then extruding to obtain the film A;   (2) according to a weight ratio, compounding the cellulose and then extruding to obtain a base layer of a cellulose film of the film B, and coating the PVDC on a surface of the base layer of the cellulose film to obtain the film B; and   (3) laminating the film A and the film B into the plastic film through an adhesive.   
     
     
         13 . A plastic bag prepared from the plastic film according to  claim 1 . 
     
     
         14 . A plastic bag prepared from the plastic film according to  claim 2 . 
     
     
         15 . A plastic bag prepared from the plastic film according to  claim 3 . 
     
     
         16 . A plastic bag prepared from the plastic film according to  claim 7 . 
     
     
         17 . A method of packaging food, comprising using the plastic bag according to  claim 13  for food packaging. 
     
     
         18 . A method of packaging food, comprising using the plastic bag according to  claim 14  for food packaging. 
     
     
         19 . A method of packaging food, comprising using the plastic bag according to  claim 15  for food packaging. 
     
     
         20 . A method of packaging food, comprising using the plastic bag according to  claim 16  for food packaging.